The measure of signal to noise ratio is used in certain engineering and scientific fields to describe something relevant and desired (signal) relative to something irrelevant or undesired (noise). Using radio as a basic example, the signal is the music (what you want to hear) while static would be considered undesirable noise that interferes with your ability to appreciate the signal.

This concept also applies to résumés. On résumés, the signal (desired content) is the sum of items that attempts to qualify the candidate for the position. The rest, with few exceptions, is noise.

When crafting a résumé, many writers take a "more is more" approach that results in unnecessary length, five-dollar words, and an abundance of bullets revealing every minute detail of a candidate's work history. This tendency is likely the result of two fallacies.

Résumés must list all professional experience.

The amount of résumé content correlates to experience and expertise.

This first fallacy is likely the result of the writer's efforts to provide career transparency, and the fear that omitting experience may be considered deceptive. Listing wholly irrelevant work is only useful to justify employment gaps and demonstrate job stability, but even then the content has dubious value. There are many cases where it is advised to omit the oldest experience, as these are almost always the least relevant positions.

The second fallacy is the mistaken theory that a lengthy résumé is more likely to impress hiring managers and recruiters, which tempts writers to include filler content. Size doesn't matter when it comes to résumés, and a large bloated résumé is less effective than a condensed version. Candidates with few qualifications and accomplishments may be more likely to overcompensate by adding irrelevant content in order to stretch to an extra page.

We all know what a barista does

When candidates list explicit details of their work experience from irrelevant past positions, they are adding noise to the résumé. Young job seekers usually list positions held during college that are irrelevant to their chosen profession. When an accountant with three years of experience applies for new accounting positions, the résumé doesn't require four bullet points explaining their duties as a barista five years ago. Even if the job is listed to demonstrate work ethic, we all know what a barista does.

What's wrong with a few extra bullets and words?

Extra bullet points and words create two problems.

Noise makes it more difficult for readers to identify the signal.

Sometimes noise can unintentionally become the signal.

If a résumé contains a single bullet point revealing a necessary qualification that is sandwiched between five irrelevant details, the reader is more likely to miss the qualifying bullet. Going back to radio, it becomes harder to hear the vocals and instruments of a song when the relative amount of static increases, and it is difficult to find important information when it is buried among unnecessary material. Keep in mind that those reviewing résumés may spend as little as a few seconds scanning the document, as a small 2012 study suggested.

Not only is the barista description described earlier an example of résumé noise, it is possible that the inclusion of these irrelevant details can become an unintended signal. The reader stops viewing the candidate as an experienced accountant and starts to see them as a barista. Returning to the radio example, when someone hears an increasing relative amount of static, there is a point where the listener starts to wonder if the static may actually be part of the song.

Avoiding noise

To minimize the noise and emphasize the signal, review your résumé line by line and decide if each sentence and bullet truly add to your qualifications as a candidate for the positions sought. Any descriptions of irrelevant jobs should be minimal. The most impressive accomplishments and responsibilities for each job should be listed first to maximize the odds a reader will see them.

Keep in mind that hiring professionals do not equate résumé length with career accomplishments, success, or seniority, so adding content simply to extend the overall size of your document only serves to create a signal to noise problem for your audience.